Control apparatus for fluid pressure actuated devices



Oct. 29, 1935. F. G. FOLBERTH ET AL 2,018,844-

CONTROL APPARATUS FOR FLUID PRESSURE ACTUATED DEVICES Filed July 28, 1932 2 Sheets-Sheet 1 ZSnventor (Ittoruegs Oct. 29, 1935. 2,018.844

CONTROL-APPARATUS FOR FLUID PRESSURE ACTUATED DEVICES .F. G. FOLBERTH ET AL Filed July 28, 1932 2 Sheets-Sheet 2 Zhwcntor Patented Oct. 29, 1935 CONTROL APPARATUS FOR FLUID PRES- SURPACTUATED DEVICES Frederick G. Folberth and William M. Folberth,

' Cleveland, Ohio Application July 28, 1932, Serial No. 625,502

4 Claims.

In our co-pending United States patent application, Seria No. 483,328, filed September 20, 1930,

of fluid pressure actuated apparatus for operating the brakes of' a motor vehicle.

Inthe present application we have illustrated above noted application. It will be understood,

I however, that our improved control apparatus is adapted for many other uses than that herein shown and described. l i

In the operation of fluid pressure actuated brakes for vehicles it is extremely important that asmooth and sensitive brake all conditions and at all points in its brake controlling movements.

To control the flow of actuatingfluid to and from the cylinder of fluid pressure brakes and the practically instantaneous changes in the fluid pressure conditions and eliminating harmful re- .sistance to flow of the operating fluid and at the same time providing a valve structure which occupies a minimum of space for its capacity. 7 6 t Other objects of our invention will appear from the following description, reference being had to the accompanying drawings, in which- Figure 1 is a fragmentary sectional side elevation of the front portion of an automobile showing our fluid pressure control apparatus applied to control the operation of the brakes of the automobile.

Figure 2 is a vertical cross section of the control valve shown in Figure 1. 155

Figure} is a plan section of our control valve taken on line 3-8 of Figure 2.

Figure 4 is a fragmentary cross sectional view illustrating the upper portion of our control valve and taken on line 4-4 of Figure 2.

t Figure 5 is a plan section taken on line 5-5 of Figure 2. v

In our above noted United States patent appli--- cation, Serial No. 483,328, we have disclosed a fluid pressure actuated brake system for automobiles 5 in which the clutch operating lever of the vehicle is adapted to control the operation of the vehicle brakes. In thepresent application we have illustrated a similar arrangement but it will be understood thatany suitable means, such as aseparate lever, may be utilized to impart the desired movement to the control apparatus. In Figure 1 we show a vehicle having a clutch operating lever or pedal l adapted tooperate the vehicle clutch, dia-' grammatically, shown at 2. lever or pedal 3 is connected by suitable rods and etc. to operate the vehicle brakes, one 'of which is generally indicated at B, andincludes the usual brake drum 4" and brake shoe or shoes 5.. The

operating cylinder of 'the fluid pressure actuated mechanism 6 carries a piston in the usual manner which is connected to apiston rod 1 which, in the installation shown, is pivotally secured at its outer end to the brake operating lever 3. It

will be understood that although we have shown 5 a cylinder and piston arrangement, a diaphragm chamber and diaphragm or other equivalent apparatusmay be substituted therefor; The cylinder 6 is connected to our control valve, generally indicated at V. bya conduit 8 and .a conduit 9 leads from the control valve to a suitable source of'actnating fluid pressure such as the intake manifold ill of the vehicle engine.

The valve V, as shown, is mounted ina vertical position on the dash board ll. of the vehicle The brake operatin 35 shown in Figure l itmay extends out from the bottom of the valve housing.

A coil spring I3 is secured to the lower end of the rod I2 and extends downwardly therefrom. At the lower end of the spring I3 we preferably provide a flexible cable or the like I4 which is provided at its lower end with an adjustable stop member I5. The cable I4 passes through a suitable aperture in the angle bracket I6 which is rigidly secured to the clutch operating lever I at I].

Before going into the details of the construction of our control valve it will be well to give a general explanation of the apparatus thus far described. When the parts are in the position be considered that the vehicle clutch pedal I has been depressed from its normal or clutch engaged position to a point where the vehicle clutch is completely disengaged. At this point the bracket I6 has been moved downwardly on the cable I4 until it is just striking the stop I5. Further movement of the clutch pedal I in clutch disengaging direction will cause a downward pull on the spring I3 which will operate the valve V to connect the intake manifold suction with the cylinder 6 and cause application of the vehicle brakes, as will be fully described later. When the operator removes his foot from the clutch pedal I it is returned to clutch engaged position by the usual clutch springs, etc., and, as the hole in the bracket I6 through which cable I4 extends is of sufficient size to permit free movement therebetween, the bracket I6 will merely slide up on the cable I4 without affecting the valve V. Thus, it will be seen that during the purely clutch operating movement of the pedal I the bracket I8 will slide up and down on the cable I4 without actuating the valve V but that, after the clutch is disengaged, further downward movement of the clutch pedal I will operate the valve V to control the vehicle brakes in the desired manner.

Referring now to Figures 2, 3 and 4, the valve V comprises a housing having an upper cylindrical portion I8 and a lower, somewhat enlarged, diaphragm chamber portion I9. A double ended piston type closure member C is freely in the cylindrical portion I8 of the valve housing and is provided with an upper closure member 28 which is adapted to control the connection of the cylinder 6 to the atmosphere and a lower closure member 2I which is adapted to control the connection of the cylinder to the source of vacuum, in the present case, the intake' manifold I8.

The two closure members 28 and 2I are connected by a central portion 22 of reduced cross sectional area and the piston member C is provided with an upwardly extending bore 23 into which the upper end of the rod I2 extends. As is clearly seen in Figure 4 the upper end of the rod I2 is pivotally connected to the piston closure member C by means of a pin 24. This pivoted connection of the rod I2 to the closure member C permits a relatively small degree of movement therebetween and eliminates the necessity of absolute accuracy in guiding the rod I2. This is helpful in that it prevents the apparatus from getting out of adjustment and eliminates the necessity of extremely close manufacturing tolerances such as would be required if the piston closure member C and the rod I2 were rigidly connected.

The diaphragm chamber portion I9 of the valve housing is provided with an end cap 25 adapted to move which has threaded engagement with the main housing and is adapted to clamp the outer periphery of a diaphragm 26. The diaphragm 28, which is preferably of rubber or other similar flexible material, is secured to the rod I2 by the shoulder member 21 and the threaded clamping member 28. Between the clamping member 28 and the end wall of the cap 25 is a spring 28 which normally holds the diaphragm 26 and the piston closure member C in the positions shown in Figure 2. To secure the most.sensitive valve action the strength of the spring 29 is preferably slightly more than enough to support the weight of the parts attached to the rod I2 when thebracket I6 is out of engagement with the stop I5. The lower end of the rod I2 is guided by the bearing portion 38 of the cap 25. The diaphragm 26 divides the diaphragm chamber into two portions. the lower f whichis connected to the atmosphere through the holes 3I in the end cap 25 and 0 portion I8 of the valve housing into the hose 25 connecting member 34, from which the conduit or hose 8 extends to the cylinder 6. Thus, it will be seen that the chamber on the upper side of the diaphragm 26 will at all times be connected to the cylinder 6 and therefore will be subject to the same'pressure conditions.

The upper end of the cylindrical portion I8 of the valve housing is closed by means of a cap member 35 which is formed with an integral supporting lug 36 which is provided with a suitable hole 31 for bolting the valve to the dash board of the vehicle, as seen in Figure 1.

a An aperture 38 is formed in the side wall of the cylindrical chamber I8 just below the end cap 35- and establishes communication between the upper end of the cylindrical chamber I8 and the atmosphere. The lower end of the cylindrical chamber I8, below the piston closure member C, is also connected to the atmosphere. through the hole 39. The atmospheric connection to the interior of the cylinder I8 between the closure members 28 and 2 I, is provided by a circumferentially extending slot 48. As seen in Figure 3 this slot 48 extends around substantially one-half of the circumference of the valve housing and thus an atmospheric connection of large cross sectional area is provided. From the end 4| of the slot 48 a groove 42 is formed in the inner wall of 'the housing I8 and extends around to the opposite end 43 of the slot 48. A similar groove 44 extends around the inner wall of the cylindrical casing I8 at the aperture 32. A suitable nipple 45 forms a connection for the conduit 9 and an elongated communicating passage 46, generally similar to passage 32, extends through the wall of the chamber I8 into the interior thereof. An annular groove 41 extends around the inner wall of the cylinder I8 from the passage '46. The purpose of the three annular grooves 42, 44 and 41 is to cause the fluid pressure, whether atmospheric or operating, tc be applied equally around the closure member: 28 and 2I and to thus eliminate any tendency for piston C to be forced to one side or the other 01 the housing I8 by the fluid pressure. The onl: resistance to movement of the piston member within the cylindrical chamber I8 other than thl required imposed by springs I3 and 29 and dia phragm 26, will be the ordinary wall friction Oi the walls of the chamber I8 and there will be m s,o1a,e44 variation in the friction of the member withvariations in the pressure applied through the openings 32, 40 and 48. v annular groove passage arrangementis of particular importance in a valve of this type which must have a few variable factors affecting it as possible in order to "secure the proper results. n

The operation of our improved valve to control the application of the vehicle brakes is as follows:

In Figure 1 the parts are shownin the position they assume when the vehicle brakes are released.

' exerted on the cable i5 In this position the conduit 8, and consequently the cylinder 6, are connected to the atmosphere through the nipple 34, the aperture 32, the in-' terior of the cylindrical housing l8 and the slotted aperture 40. Now. if a downward pull is the spring it will be placed in tension and the rod l2, the diaphragm 26 and the closure member C will be moved downwardly. The first portion of the downward movement of the piston member 0 will cause the portion 20 thereof to close the slot 40 and thus disconnect the cylinder 6 from the atmosphere.

After the slot 40 is closed a slight further downward movement of the piston member 0 will cause the upper face of the closure member 2| to move-below the upper edge of the slotted aperture 48 and communication will be established between the cylinder 6 and the intake manifold suction through the conduit 8, the nipple 34, the aperture 32, the interior of the cylindrical chamber l8, the aperture conduit 9. When this occurs the pressure will be reduced within the cylinder 6 and the piston will be moved downwardly to apply the vehicle brakes. At the same time the pressure will be reduced on the upper side ofthe diaphragm 26 because of' the connection 33. When the reduction in pressure on the upper side of the diaphragm 26 becomes sumciently great the differential between the reduced pressure on the upper side and the atmospheric pressure on the lower side of the diaphragm 26 will be sufiicient to overcome the spring l3, and the diaphragm 28, together with the rod =|2 and piston member 0, will move upwardly until the closure 2| closes oil the slotted nection to again be opened, or until the tension on the spring i3 is relieved permitting the atmospheric connection to the cylinder to be opened.

By providing the enlarged diaphragm 26 we are able to use a relatively stifl spring l3 and thus the grooves 42, 44 and 41 prevent any tendency toward binding of the piston member 0 within the cylinder l8 they eliminate the necessity of extremely accurate fitting of these parts, thus making an apparatus which may be more economically constructed and which also is not aifected by ordinary wear. As the degree of vacuum apdltional resi the control valve V to place 46, the nipple 45 and the appended claims.

I I" are preferably such that the initial tension on 10 the spring l3. which is caused by the bracket l6 just resting against the stop l5, will create and maintain pressure conditions within the cylinder 8 which will just take up the slack in the brake connections and bring the brake shoes in contact with the brake drums without, however, creating any noticeable braking eflect.

- Thus, in operating the vehicle the driver will disengage his clutch by pushing down on the pedal I until he feels the bracket Hi just strike the stop l5. This striking action will operate the brake linkage and shoes in condition for immediate operation and any further downward movement of the pedal 1 will cause a corresponding braking force to be applied to the brake drums.

Although we have described the illustrated embodiment of 0m invention in considerable detail it will be understood that modifications and variations may be made therein without departing from the spirit of our invention. For example, by changing the characteristics of the spring I 3 the same apparatus may be adapted for cylinder'and piston may be controlled and, by

' varying the strength of the springv l3, this maximum braking force may be varied for diiferent 40 types of vehicles. We do not, therefore, limit ourselves to the specific apparatus shown and described but claim as our invention all embodiments thereof coming within the scope of the v We claim: 7 1. In combinationin a control valve for controlling the application of actuating pressure to a cylinder or the like, a cylindrical housing havthrough said passages, said closure member moving means including a diaphragm housing at one I end-of said cylindrical housing and disposed coainally therewith, a flexible diaphragm in said housing, connections between said diaphragm and said closure member, said diaphragm being exposed on one side to-the atmosphere and on the other sideto the efl'ective fluid pressure in said cylinder, spring means for normally maintaining said diaphragm and closure member in oil! position and operating means for moving said diaphragm and closure member into open position, 66

said means including a resilient member adapted to impose a load on a. A control valve for fluid pressure actuated devices comprising a housing having a cylindrical Portion and a diaphragm chamber portion, said cylindrical portion and diaphragm chamber portion having a common end wall, a diaphragm in said diaphragm chamber, a rod secured to said diaphragm and extending therefrom into said cylindrical portion through said common end wall. a piston secured to said rod and disposed within said cylindrical portion, said piston including a pair of connected closure members, one of said closure members being adapted to control an atmospheric connection to the interior of said cylinder and the other of said closure members being adapted to control an actuating fluid pressure connection to the interior of said cylindrical portion, said cylindrical portion being provided with an operating pressure port between said closure members adapted to be connected to the fluid pressure actuated device, a fluid conducting passage extending from the interior of said cylinder between said connected closure members to one side of said diaphragm, the opposite side of said diaphragm being exposed to the atmosphere, a spring secured to the end of said rod and means for applying a valve operating force to said rod through said spring. 1

3. A control valve for fluid pressure omrated devices comprising a housing having cylindrical chambers arranged in end to end relation and having a common end wall therebetween, a piston type valve closure member in one of said chambers, means movable by fluid pressure in the other chamber, fluid pressure conducting connections whereby said movable means will be acted on by the fluid pressure supplied to the fluid pressure operated device, an operating rod connecting said closuremember and said means movable by fluid pressure, said rod extending through said common end wall and also extending outwardly of said housing from said fluid pressure movable means, a spring associated with the outwardly extending portion of said rod, and means for applying a valve operating force to said rod through said spring.

4. A control valve for devices, comprising a housing having a cylindrical bore portion and a diaphragm chamber portion, a diaphragm in said diaphragm chamber, a rod adapted to be moved by said diaphragm, and extending from said diaphragm chamber into said cylindrical bore portion, a piston valve member secured to said rod and disposed within said cylindrical bore portion, said piston member including spaced, connected closure members, one of said closure members being adapted to control an atmospheric connection to the interior of said cylindrical bore and the other of said closure members being adapted to control an actuating fluid pressure connection to the interior of said cylindrical bore, said cylindrical bore portion being provided with an operating pressure port between said closure members adapted to be connected to the fluid pressure actuated device, a fluid conducting passage extending from the interior ofsaid cylindrical bore between said connected closure members to one side of said diaphragm, the opposite side of said diaphragm being exposed to the atmosphere.

FREDERICK G. FOLBERTH. WILLIAM M. FOLBERTH.

fluid pressure actuated- 

